Years ago - looooong before electronic communications - teams had ‘messengers’ (for lack of a better term) that ran onto the field and called the play in the huddle, then ran back off the field. At some point, the Rules Committee decided that wasn’t a good look for NCAA football, and changed the substitution rule to require a sub who became a player - as defined - to remain in the game for at least one down. After that rule, hand signals became the primary means of communication. That was followed by signs, and combinations of hand signals and signs. As we all know, now, they have electronic communications directly to the players. So, violations of this rule have virtually totally disappeared. If you see technical violations of this rule, it is ALWAYS a case of confused players trying to figure who is supposed to be in the game. We can almost always tell confusion from subterfuge, and we just pass on making any sort of call, that no one except us know exists, anyway.
